Degradation of reactive dyes wastewater supplemented with cationic polymer (Organo Pol.) in a down flow hanging sponge (DHS) system

Decolourization of reactive dyes wastewater supplemented with 1 mg/l cationic polymer (Organo Pol.) in a down flow hanging sponge (DHS) system was investigated at different HRTs and OLRs. The results obtained revealed that, increasing the HRT from 1.7 to 5 h, significantly increased the removal efficiencies of color and COD i.e. at a HRT of 5 h, and OLR not exceeding 2.8 g COD/l d, the reactor achieved removal efficiencies of 66.5 ± 7.07% for COD t and 90.12 ± 3.13% for color. However, at longer HRT of 6.0 h, the decolorization process was substantially dropped, due to high salinity content in the influent.